Film.



OZIAS DODGE, OF NORWICH, CONNECTICUT.

FILM.

Specification of LettersPatent.

Patented Dec. 24,1907.

Application filed August 30.1906. Serial No- 832.623.

To all whom it may concern:

Be it known that I, OZIAS Donen, a citizen of the United States, and a resident of Norwich, in the county of New London and State of Connecticut, have invented an improvement in Films employed in drawing and other artistic and industrial work, and specially employed in making transparent positives and negatives, with or without the use of photography, in making the films.

This invention concerns the steps which )recede the makin of a printing surface om a drawing or design, original or other.

The objects of my invention are to furnish the best surface on which to execute drawings or designs, semi-opaque, grained or otherwise, as the work may require, such that in the progress of the drawing the work may be erased or changed, and that afterwards the lines may be made immovable upon the surface, and the surface bearing the drawing or design may be easily converted into a trans arent support thereof.

Anot or object of my invention is to provide a film which, when su porting the drawing or design, and renders transparent, may be a plied as a positive direct u on the surface of a hotographically coate metal plate to pro uce a printing surface on the plate, thereby saving several photographic processes.

A further object is to provide a support for the original drawing or design that is flexible in having various surfaces adapted to' different kinds of work, that, when converted into a transparent support, can be used for making printing surfaces indefinitely without destruction of the film or harm to it.

Other objects will appear from the hereinafter description. 7

In drawing upon a white surface with a photographically opaque pencil or ink, and

om this drawing, producing by photography, transparent. positives or negatives, there are several operations in each of which something of the vital touch of the original is lost, whereas in my process the original is the positive or negative, thereby saving time, expense, and most of all, preserving the slightest touch of the original.

Prior to my invention there was no -surface upon a support that is semi-transparent, and that after drawing may be made entirely transparent, bearmg the drawing firmly fixed upon its surface.

In Letters Patent of the United States issued-to me on a process of producing printing surfaces, No. 758,625, dated May- 3rd,"

stone and zinc in lit ograp y, the original is lost, while by the use of my improved filmit is in no way injured and can be used indefinitely.

. he tracing paper or cloth employed by architects, from which, as a positive or negative, blue-prints are produced, is inapplicable in attaining the objects of my present invention, for no tracing aper or cloth is entirely transparent, and this is necessary in producing the ima e upon copper. Sheet gelatin and cellu oid are objectionable in that they have no grained and semi-transparent surface suitable to draw u on.

I wil now describe in detail the preferred way of making my improved semi-transparent film with a grained surface of any desired fineness, and the process of converting it, after the drawing is placed 11 on it, into a perfectly transparent support or the drawsurface of the film. To make this lass surface I take a sheet of plate glass, sprinkle fine sand thereon, and upon it place a level lithographic stone, and with the aid of water, and by revolving the stone upon the surface of the glass, I grind the glass to a sharp tooth or grain of any desired fineness, at will, by graduating the sand. This grained sheet or glass is then washed clean and-rubbed with powdered talc and turpentine to prevent the removal of the ain in the further steps. Next gelatin, Ne sons No. 2, is dissolved in water and poured onto the grained glass warm, and allowed to set and dry upon the surface from twent -four to thirty-six hours. The sheet of ge atin is then peeledoff and is found to have a sharp grain, and to be semitransparent, well adapted to be laced over a drawing to be copied, and is exible and presents anv ideal surface for the artist to work upon. Upon the grained surface of this film the drawing may be made with a pencil, preferably hard red, because such a pencil is lithographically opaque. The drawmg may be erased at will, or scratched out, as may be done with a lithographic stone, or

it may be worked with a brush or with. pen

and ink, or as a mezzo-tint, up to the step next to be described.

After the drawing is complete, the sheet of gelatin bearin the drawin is flowed over with flexible collodion, whic permanently fixes the drawing, and at the same time renders the gelatin support transparent. Both sides of the sheet may be varnished as a protection from moisture and handling. Having thus made the film transparent, and having fixed the photographically opaque lines, I now have a transparent ositive which may be applied to a sensitize copper plate, or otherwise used in making accurate and vital reproductions upon suitable surfaces.

In producing an etched plate I place this drawing, thus prepared, in a printing-frame,

face to face with a coated copper plate, as in the usual half-tone work, or use it to build up a plate by the Dodge process heretofore mentioned as patented to me.

When I use the expression grained film I mean a homogeneous flexible film, one surface of which has a grain on it, produced either in the manner above indicated or by 3 some other equivalent means.

What I claim and desire to secure by Letters Patent is:

1. A semi-transparent grained film adapted to be rendered transparent. 3. 2. A semi-transparent, grained, elatin film adapted to receive drawings, whic may be rendered permanent by flowing the film with flexible collodion, and adapted to be rendered transparent.

3. A grained film adapted to receive drawings directly u on its surface.

4. A graine film adapted to receive drawings which ma be rendered ermanent;

which film is a apted to be renc ered transparent.

5. A rained film adapted to receive draw in s anrIto use as a negative in photography. n witness whereof I have hereunto set my hand at Sandwich in the county of Carroll and State of New Hampshire, this 24 day of Aug, 1906.

OZIAS DODGE. In presence of.

E. M. HEARD, S. C. TOZZER. 

